Low-level laser therapy for accelerating orthodontic tooth movement: a Meta-analysis and systematic review

To evaluate the efficacy and related risk of low level laser therapy (LLLT) for accelerating tooth movement during orthodontic treatment.

An extensive electronic search was conducted by two reviewers. Randomized controlled trials (RCTs) and quasi-RCTs concerning the efficacy of LLLT for accelerating tooth movement during orthodontic treatment were searched in CENTRAL, PubMed, Medline, Embase, CBM, CNKI.

Six RCTs and three quasi-RCTs, involving 211 patients from six countries, were selected from 173 relevant studies. All nine articles were feasible for the systematic review and meta-analysis, five of which were assessed as moderate risk of bias, while the rest were assessed as high risk of bias. The mean difference and the 95 % confidence interval (95 % CI) of accumulative moved distance of teeth were observed among all the researches. The results showed that the LLLT could accelerate orthodontic tooth movement in 7 days (MD = 0.19, 95% CI 0.02-0.37, P = 0.03) and 2 months (MD = 1.08, 95% CI 0.16-2.01, P = 0.02). Moreover, a relatively lower energy density (2.5, 5 and 8 J/cm²) was seemingly more effective than 20 and 25 J/cm² and even higher ones.

This systematic review and meta-analysis demonstrated that LLLT might speed up the tooth movement in orthodontic treatment. A relatively lower energy density (2.5, 5, and 8 J/cm²) was seemingly more effective than higher ones. More qualified RCTs in human subjects are required.